Tankless pumping system



Nov.`22, 1966 R. F. scHAUB 3,286,636

TANKLESS PUMPING SYSTEM Original Filed April l, 1963 v means bring United States Patent O 3,286,636 TANKLESS PUMPING SYSTEM Robert F. Schaub, La Grange, Ill., 'assignor to Syn.cro Flo,

Inc., Downers Grove, Ill., a corporation of lllmois Original application Apr. 1, 1963, Ser. No. 269,515, iiow Patent No. 3,195,555. dated July 20, 1965. Divided and this application Apr. 9, 1965, Ser. No. 454,238

3 Claims. (Cl. 103-25) This application is a divisional application of my application, Serial No. 269,515, now U.S. Patent No. 3,195,555. i

This invention relates to a tankless pumping system and more particularly to a system for boosting water supply pressure for multi-story buildings, and the like.

Pressure booster systems have heretofore been employed in mostrelatively tall buildings to increase the pressure of the water' as supplied through city mains for serving all of the floors of the building, including the upper tloors. One such system is more particularly described and claimed in my co-pending application Serial No. 227,115, filed September 26, 1962, now patent No. 3,198,121. Such systems generally tend to maintain the same pump pressure regardless of fluctuations in demand, which normally results in a lower available pressure at the fixtures at times of high demand due to lfriction losses in the piping.

Itis accordingly the principal object of the present iriventiori to provide a tankless pumping system which will vary the pumping pressure as the demand changes to compensate for the fraction losses, thus maintaining a substantially constant pressure on all fixtures regardless of flow demand.

Another object is to provide a tankless pumping system in which a plurality of pumps are connected in parallel and are provided with pressure lregulators set at different values `and further including control means to cause only the pump connected with the lower pressure regulator to operate below a predetermined demand rate Iand .to cause both pumps to operate at a higher demand rate while at the same time causing the control for the lower pressure regulating valve to be bypassed. I

According to a feature of the invention, the system comprises pumps of different sizes with the smallest pump having a pressure regulator set at a lower value and the controlling means functions to bring the smaller pump, then the larger pump, then both pumps, into operation as the demand rises. At the fhigh demand when both pumps are functioning the pilot -control for the pressure regulator for the smaller pump is bypassed so that the smaller pump can supply water to the main outlet line.

Systems employing three or more pumps are also contemplated in which the regulator for the pumps are set to maintain progressively higher values with the control ing the pumps into operation in different combinations to satisfy different demand rates and simultaneously causing the pilot controls for .the lower pressure regulators for the pumps then in operation'to be bypassed. A preferred combination which gives maximum economy of` installation and oper-ation utilizes a small pump of about v25% of system peak flow rate regulated to the lowest pressure and two larger pumps each of'about 55% of system peak ow rate regulated to progressively higher sure. pr'elhe above and other objects and features of the invention will be more readily apparent from the following description when read in connection with the accompanying drawing, in which:

FIG. 1 is a diagrammatic view of a tankless pumping system embodying the invention; and

FIG. 2 is an operating diagram.

The system, as shown, takes water from a supply source,

indicated at 10, which may be the usual city water main or may lead to a tank or well which may or may not have a separate pump. The water taken from the source is pumped under increased pressure into a water supply conduit 11 which leads to various points of demand throughout the building.

In the system, as illustrated, three pumps are employed the first of which, indicated at 12, is a relatively low capacity pump, and the second and third of which, indicated at 13 and 14, are of greater capacity. The pumps 13 and 14 may be of the same capacity or of diiferent capacities depending upon the exact system requirements, but are normally of the saine capacity. Each of the pumps discharges into the water supply conduit 11 through a pressure regulating valve, indicated generally at 15. The lower pressure regulating valve for the pump 12 is illustrated dia-grammatically and it will be understood that the other pressure regulating valves may be of similar construction.

As shown, each of the pressure regulating valves 15 comprises a main valve 16 movable toward and away from a port 17 through which water ilows from the inlet to the outlet of the pressure regulating valve. The valve 16 is moved toward and away from the port 17 to throttle it more or less by a `diaphragm 18 which is subjected on its lower surface to the discharge pressure of the regulating valve and on its upper surface to a pilot controlling pressure. The pilot controlling pressure is produced by a pilot regulator which is generally similar to the main regulator, as so far described, including a pilot valve 19 controlling a port 21. The valve 19 regulates the ow of water through a pilot conduit 22 leading from the discharge side of the pump to the upper side of the diaphragm 18. The valve 19 is controlled by a diaphragm 23 which is urged downwardly to open the valve 1 9 by a spring 24 which can be adjusted through an adjusting screw 25 to regulate the pilot pressure. In order to open the valve 16 fully when desired, as explained hereinafter, a solenoidcontrolled bypass valve 26 connects the conduit 22 directly to the upper surface of the diaphragm 18, as shown. The valve 26 is normally closed and is opened when its operating solenoid is energized.

The pressure regulator for the pump 124is adjusted to a relatively low pressure and the regulators for the pumps 13 and 14 are adjusted for progressively higher pressures. As will appear hereinafter, this will produce an increased pressure supply to the supply conduit 11 in response to higher demands so that the pressures available at the various fixtures throughout the building will be maintained substantially constant. The pumps are driven respectively by motors 27, 28 and 29 which are shown as electric motors, although any other `desired type of motor could be used. One side of each motor and one of the terminals of each of the solenoid valves 26 is connected to one side of a power source, indicated at 31. Circuits through t'he motors and solenoid valves are completed under the control of `a flow regulator 32 which is responsive to the flow through the supply conduit 11. For this purpose, theow regulator may be connected through conduits 33 to the opposite sides of an orice or restriction 34 in the ow conduit. The iiow regulator may be any desired type of commercial unit which will progressively operate switches to control circuits to the several motors and solenoid valves as the flow changes.

It is one of the features of the invention that the several pumps can be so proportioned and controlled with respect to each other as lto provide the most economical system from the Vstandpoint of cost and installation and of operation. lFor this purpose, the pump 12 is selected to have a capacity of aproximately 25% of -the peak system demand and the pumps 13 and 14 are selected so that each of them has a capacity of approximately 55% of the peak system demand. In this way, the full peak demand of the system can be satised by operating the two pumps 13 and 14 simultaneously and demands less than the peak demand can be satisfied by operating individual pumps or other combinations of pumps which will provide sumcient capacity to satisfy the existing demand without producing excessive capacity. n one typical installation, 'as illustrated in the operating diagram, FIG. 2, the flow regulator is adjusted to close a circuit only to the motor 27 for the rst pump when the capacity is below of peak demand. Therefore, at low demands only this relatively small pump is being operated so that excessive pumping is eliminated or minimized and the operating cost is minimized. Should there be long periods of zero or substantially zero demand, there would be altendency for the water to heat due to operation of the iirst pump without any flow or with minimum flow therethrough. Should this condition con- 'tinue for a long period of time the water could be heated to an excessive temperature. In order to avoid this a waste Valve 37 is provided connected to the waste line and is controlled by a bulb 38 at the outlet to the pump 12 to open when the temperature exceeds a predetermined value. The bulb 38 may also be located within the pump itself, Thus if the water should be excessively heated due to friction caused by operation of the pump at times of zero or minimum demand, the waste valve 37 will be opened to permit some of the heated water to flow to the sewer` thereby admitting fresh cool water to the pump to prevent its temperature from rising to an excessive value.

When the demand for water by the system exceeds 25% of the peak demand the 110W regulator 32 will interrupt the circuit to the motor 27 and will close a circuit to the motor 28 to cause the second pump only to operate. This pump can satisfy the demand up to 55% of the -peak value and will continue to operate alone until the peak demand exceeds the 55% figure. When this occurs, the 110W regulator 32 will operate to again energize the motor 27 and will simultaneously energize the solenoid valve 26 for the first pressure regulator. Under these conditions, both pumps 12 and 13 will supply water to the supply conduit 11, but the pressure regulator for the pump 12 Will be wide open so that its discharge pressure is unregulated. The pump 12 will therefore supply water to the supply conduit 11 at a rate proportional to a function of the pumps head capacity curve, the pressure for which the `second regulator 15 is set and the system flow demand. Under these conditions, pumps 12 and 13 can pump water into the supply conduit 11 and their total capacity will supply water at a rate up to about 80% of the peak system demand.

It will be noted that the great majority of system requirements can be satisfied by this combination of two pumps since the system will exceed 80% of the peak demand only on relatively rare occasions and for relatively short intervals. It will therefore rarely be necessary to operate both of the larger pumps 13 and 14 simultaneously although preferably these pumps may be alternated by changing the controls so that first one and then the other will function as the second pump. This is desirable to prevent any one pump from remaining inactive for an excessive period of time which might lead to the possibility of rusting or freeze-out. The changeover can be effected very simply by switching the controls in the flow regulator and by re-adjusting the pressure regulators 15 for the respective pumps.

Should the'demand increase above 80% of the peak demand, however, the flow regulator 32 will function to de-energize the motor 27 and to energize both motors 28 and 29, as well as the bypass valve 26 for the second regulator. At this time, the two larger pumps will operate simultaneously to provide a nominal capacity of of the peak demand. At the same time, the pressure regulator for the second pump which is set to a lower value than the pressure regulator for the third pump will be made ineiective so that both pumps can supply water to the supply conduit simultaneously and at a higher pressure.

While the exact pressures for which the regulators are adjusted will vary from system to system, it is contemplated that the regulator for pump 12 will be set for several pounds less than the regulator for pump 13 which will in turn be set several pounds lower than the regulator for pump 14. Assuming that it is desired to maintain a pressure of about 70 pounds per square inch in the supply conduit 11, the regulator for the smaller pump 12 might be set for about 67 pounds per square inch, the regulator for pump 13 for 70 pounds per square inch and the regulator for pump 14 for 73 pounds per square inch. With these settings, when the demand for water is low and flow through the pipe is low so that the drop is minimal, water will be delivered to the system at a relatively low pressure approximating that desired at the xtures. As the demand increases, and the pressure drop due to flow correspondingly increases, the pumping system will supply water at a higher pressure to the main supply conduit so that the discharge pressure at the various fixtures will be maintained substantially constant.

While one embodiment of the invention has been shown and described herein, it will be understood that it is illustrative only and not to be taken as a definition of the scope of the invention, reference being had for this purpose to the appended claims.

What is claimed is:

1. A tankless pumping system comprising a pump connected between a source and a line conduit, a pressure regulator connected between the said pump and the conduit for controlling pressure supplied to the conduit by the said pump, and means responsive to the flow through the conduit for controlling said pump and said pressure regulator to limit the pressure in the conduit to a relatively low value when the ow through the conduit is below a predetermined value and to allow the pressure to increase above the said low value when the flow is above said predetermined value, and to cause said pump to stop operating when said flow is belowk said predetermined value and to cause said pump to commence operating when said flow increases above said predetermined value.

2. The system of claim 1 wherein said ow responsive means ydisables said pressure regulator when said flow is above said predetermined value and to cause said pressure regulator to be operative when said ow is below said predetermined value.

3. The system of claim 2 wherein said system includes a solenoid operated valve which disables said pressure regulator when said flow is above said predetermined value.

References Cited by the Examiner UNITED STATES PATENTS 1,515,911 11/1924 Terry 137-4848 2,411,574 11/1946 Hunt 103-42 2,512,799 6/1950 Huber 103-1 2,562,615 7/1951 Huber 103-1 2,747,598 5/ 1956 Wooldridge 103-21 2,806,481 9/1957 Faust 13H-484.8 2,829,664 4/ 1958 Mountford 103-21 2,830,616 4/1958 Tatum 137-4842 2,837,241 6/1958 Griswold 137-4842 2,982,216 5/1961 Huber 103-21 3,086,548 4/1963 Galiger 137-4848 3,103,891 9/1963 Fulton 103-42 LAURENCE V. EFNER, Primary Examiner. 

1. A TANKLESS PUMPING SYSTEM COMPRISING A PUMP CONNECTED BETWEEN A SOURCE AND A LINE CONDUIT, A PRESSURE REGULATOR CONNECTED BETWEEN THE SAID PUMP AND THE CONDUIT FOR CONTROLLING PRESSURE SUPPLIED TO THE CONDUIT BY THE SAID PUMP, AND MEANS RESPONSIVE TO THE FLOW THROUGH THE CONDUIT FOR CONTROLLING SAID PUMP AND SAID PRESSURE REGULATOR TO LIMIT THE PRESSURE IN THE CONDUIT TO A RELATIVELY LOW VALUE WHEN THE FLOW THROUGH THE CONDUIT IS BELOW A 